INFO: task syz.9.768:11704 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.9.768 state:D stack:28552 pid:11704 tgid:11685 ppid:11063 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7289 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244 inode_lock include/linux/fs.h:1028 [inline] open_last_lookups fs/namei.c:4586 [inline] path_openat+0xb5e/0x38a0 fs/namei.c:4833 do_file_open+0x23e/0x4a0 fs/namei.c:4865 do_sys_openat2+0x113/0x200 fs/open.c:1366 do_sys_open fs/open.c:1372 [inline] __do_sys_openat fs/open.c:1388 [inline] __se_sys_openat fs/open.c:1383 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1383 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f40f966c819 RSP: 002b:00007f40f78a5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f40f98e6090 RCX: 00007f40f966c819 RDX: 000000000000275a RSI: 0000200000000040 RDI: ffffffffffffff9c RBP: 00007f40f9702c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f40f98e6128 R14: 00007f40f98e6090 R15: 00007ffdaae4d258 INFO: task syz.9.768:11707 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.9.768 state:D stack:26688 pid:11707 tgid:11685 ppid:11063 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7289 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244 inode_lock include/linux/fs.h:1028 [inline] open_last_lookups fs/namei.c:4586 [inline] path_openat+0xb5e/0x38a0 fs/namei.c:4833 do_file_open+0x23e/0x4a0 fs/namei.c:4865 do_sys_openat2+0x113/0x200 fs/open.c:1366 do_sys_open fs/open.c:1372 [inline] __do_sys_open fs/open.c:1380 [inline] __se_sys_open fs/open.c:1376 [inline] __x64_sys_open+0x11e/0x150 fs/open.c:1376 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f40f966c819 RSP: 002b:00007f40f7884028 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007f40f98e6180 RCX: 00007f40f966c819 RDX: 00000000000000e7 RSI: 000000000004027e RDI: 0000200000000200 RBP: 00007f40f9702c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f40f98e6218 R14: 00007f40f98e6180 R15: 00007ffdaae4d258 INFO: task syz.9.768:11714 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.9.768 state:D stack:27176 pid:11714 tgid:11685 ppid:11063 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7289 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244 inode_lock include/linux/fs.h:1028 [inline] open_last_lookups fs/namei.c:4586 [inline] path_openat+0xb5e/0x38a0 fs/namei.c:4833 do_file_open+0x23e/0x4a0 fs/namei.c:4865 do_sys_openat2+0x113/0x200 fs/open.c:1366 do_sys_open fs/open.c:1372 [inline] __do_sys_openat fs/open.c:1388 [inline] __se_sys_openat fs/open.c:1383 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1383 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f40f966c819 RSP: 002b:00007f40f7461028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f40f98e6270 RCX: 00007f40f966c819 RDX: 0000000000101042 RSI: 0000200000000040 RDI: ffffffffffffff9c RBP: 00007f40f9702c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f40f98e6308 R14: 00007f40f98e6270 R15: 00007ffdaae4d258 INFO: task syz.9.768:11719 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.9.768 state:D stack:28096 pid:11719 tgid:11685 ppid:11063 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7289 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244 inode_lock_nested include/linux/fs.h:1073 [inline] __start_dirop fs/namei.c:2929 [inline] start_dirop fs/namei.c:2940 [inline] filename_create+0x200/0x370 fs/namei.c:4928 filename_mkdirat+0xd2/0x520 fs/namei.c:5265 __do_sys_mkdirat fs/namei.c:5293 [inline] __se_sys_mkdirat+0x35/0x150 fs/namei.c:5290 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f40f966b687 RSP: 002b:00007f40f703de58 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f40f703dee0 RCX: 00007f40f966b687 RDX: 00000000000001ff RSI: 0000200000000300 RDI: 00000000ffffff9c RBP: 0000000000000000 R08: 0000200000000240 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000300 R13: 00007f40f703dea0 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 2 locks held by kworker/u8:0/12: #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc90000117c40 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc90000117c40 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 1 lock held by khungtaskd/37: #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:9/1336: #0: ffff88801f6a8938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff88801f6a8938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc900061b7c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc900061b7c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffff888039a8c0d0 (&type->s_umount_key#68){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:565 #3: ffff88805fa21f28 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108 2 locks held by getty/5552: #0: ffff888036ed70a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e762e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211 1 lock held by udevd/5859: #0: ffff888019c4f238 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_dop_revalidate+0x9e/0x5e0 fs/kernfs/dir.c:1185 2 locks held by kworker/u8:12/9806: 4 locks held by syz.9.768/11687: 2 locks held by syz.9.768/11704: #0: ffff888039a8c480 (sb_writers#20){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff88805fa222f8 (&type->i_mutex_dir_key#15){++++}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #1: ffff88805fa222f8 (&type->i_mutex_dir_key#15){++++}-{4:4}, at: open_last_lookups fs/namei.c:4586 [inline] #1: ffff88805fa222f8 (&type->i_mutex_dir_key#15){++++}-{4:4}, at: path_openat+0xb5e/0x38a0 fs/namei.c:4833 2 locks held by syz.9.768/11707: #0: ffff888039a8c480 (sb_writers#20){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff88805fa222f8 (&type->i_mutex_dir_key#15){++++}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #1: ffff88805fa222f8 (&type->i_mutex_dir_key#15){++++}-{4:4}, at: open_last_lookups fs/namei.c:4586 [inline] #1: ffff88805fa222f8 (&type->i_mutex_dir_key#15){++++}-{4:4}, at: path_openat+0xb5e/0x38a0 fs/namei.c:4833 2 locks held by syz.9.768/11714: #0: ffff888039a8c480 (sb_writers#20){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff88805fa222f8 (&type->i_mutex_dir_key#15){++++}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #1: ffff88805fa222f8 (&type->i_mutex_dir_key#15){++++}-{4:4}, at: open_last_lookups fs/namei.c:4586 [inline] #1: ffff88805fa222f8 (&type->i_mutex_dir_key#15){++++}-{4:4}, at: path_openat+0xb5e/0x38a0 fs/namei.c:4833 2 locks held by syz.9.768/11719: #0: ffff888039a8c480 (sb_writers#20){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff88805fa222f8 (&type->i_mutex_dir_key#14/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline] #1: ffff88805fa222f8 (&type->i_mutex_dir_key#14/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2929 [inline] #1: ffff88805fa222f8 (&type->i_mutex_dir_key#14/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2940 [inline] #1: ffff88805fa222f8 (&type->i_mutex_dir_key#14/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:4928 1 lock held by syz-executor/12767: #0: ffff888019c4f238 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_remove_by_name_ns+0x3d/0x130 fs/kernfs/dir.c:1717 1 lock held by syz.3.971/13709: #0: ffff888060a540d0 (&type->s_umount_key#59/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xac0 fs/super.c:345 1 lock held by rm/13744: 1 lock held by syz.5.973/13747: 1 lock held by udevadm/13746: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xfd9/0x1030 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 3 Comm: pool_workqueue_ Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:remove_class_from_lock_chain kernel/locking/lockdep.c:6197 [inline] RIP: 0010:remove_class_from_lock_chains kernel/locking/lockdep.c:6236 [inline] RIP: 0010:zap_class+0xcf/0x340 kernel/locking/lockdep.c:6281 Code: 49 81 fc 00 00 08 00 0f 84 a4 01 00 00 4e 8b 2c e5 20 a4 12 93 4d 85 ed 0f 94 c0 49 83 c5 f8 0f 94 c1 08 c1 75 d7 45 8b 75 00 <41> f6 c6 fc 0f 84 e1 00 00 00 41 c1 ee 08 4a 8d 1c 75 f0 a3 57 92 RSP: 0000:ffffc90000087c50 EFLAGS: 00000046 RAX: 000000000008ad00 RBX: ffffffff9268fef8 RCX: 000000000008ad00 RDX: ffffffff9352a438 RSI: ffffffff9352a438 RDI: ffffffff93045d08 RBP: ffffffff9356a890 R08: ffffffff81add068 R09: ffffffff8ddcb980 R10: dffffc0000000000 R11: fffffbfff1ed4ef7 R12: 0000000000046afd R13: ffffffff93798c10 R14: 00000000062d5308 R15: 0000000000001049 FS: 0000000000000000(0000) GS:ffff888126432000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4694bae000 CR3: 0000000052822000 CR4: 00000000003526f0 Call Trace: __lockdep_free_key_range kernel/locking/lockdep.c:6407 [inline] lockdep_unregister_key+0x1c3/0x350 kernel/locking/lockdep.c:6609 wq_unregister_lockdep kernel/workqueue.c:4903 [inline] pwq_release_workfn+0x6e7/0x880 kernel/workqueue.c:5199 kthread_worker_fn+0x509/0xb70 kernel/kthread.c:1025 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245